Growing herbs in water makes it easier to control your plants growth conditions, it takes up less space, and produces bigger and healthier plants. Easiest/most common herbs to grow in water from cuttings (propagate) are lemon-balm, mints, basil, sage, thyme, and oregano. Rosemary also works, but will take longer to sprout roots. Herbs like ginger, turmeric, and garlic might not do very well.
- Tap or bottled water (avoid distilled water)
Choose a stem that is a good 4-6" tall, and looks healthy and strong, and cut it below a leaf joint. You can also buy cut herb stems in the produce section of your grocery store. A good example:
Next, strip the bottom leaves so that about ½-¾ of the stem is bare.
Then use scissors to make a slanted cut right below the lowest leaf joint. The area that the leaves grow out of, leaf joints or nodes, have a lot of meristem cells, which form a callus over the cut and sprouts roots. And cutting at a slanted angle increases the surface area for both water and nutrient uptake.
After this, place the stem in a jar of (not distilled) water, and place the jar somewhere moderately sunny (depending on the needs of the herb). (Source for pictures)
You don’t NEED to do much else after this, but it would likely appreciate some help. Add a rooting hormone to the water, which will stimulate the stem to grow roots and contains a fungicide to prevent the cut from rotting. You can buy a premade rooting hormone, such as this one, or you can make your own using willow twigs. Here’s a DIY.
Also, plants usually get their nutrients from the soil, but since we aren’t using soil here, we will have to provide nutrients for the plant by adding it to the water. Again, this is something that many people do well without, but it will likely give better results. You don’t need much, certainly not as one would with an entire hydroponics system with a nutrient reservoir. Just add a drop or two when the roots start growing (about two weeks in), and maybe once a month after that when you change out the water. You can buy liquid plant food like this one.
Finally, changing the water can depend on what plant you have, such as lemon balm which needs to have its water changed weekly. If you are using an opaque container, algae won’t form as quickly as it would in a clear one, and doesn’t need to be changed quite as often. Generally, more or less every three weeks or when the water is a bit murky should be fine. Done!
